Searchlight-electrode-controlling mechanism



Aug. 11, 1925. a

A. (I. MABY SEARCHLIGHT ELECTRODE CONTROLLING MECHANISM Original Filed April 1, 1918 54 46 "M 47 I v ,50 32 Patented Aug. 11, 1925.

UNITED, STATES 1,549,200 PATENT OFFICE.

ADELIBEB'I. G. IVIABY, OF RICHMOND HILL, NEW YORK, ASSIGNOR TO THE SPEBRY GYROSCOPE COMPANY, OF BROOKLYN, NEW YORK, A CORPORATION OF NEW YORK.

SEARCHLIGHT ELECTRODE-CONTROLLING MECHANISM.

Original application filed April 1, 1918, Serial No. 225,947. Divided and this application filed December 3, 1920. Serial No. 427,940.

This invention relates to are lamps and.

especially to are lamps adapted for use in projectors. More specifically the invention relates to the electrode feed mechanism for such projectors. The present invention is a division of my copending application, Serial No. 225,947, for positlonlng and rotating 7 means for electrodes, filed April 1, 1918.

In electric arc lights used for searchlights or similar purposes and especially in high intensity are lights, it is well known that the greater portion of the light emanates from the crater of the positive electrode or the immediate vicinity thereof. It is, therefore, important to maintain this crater at a substantially fixed point with reference to the parabolic mirror, lens, or other condensing means employed. Furthermore, in order to obtain the'proper lighting results, it is mportant to cause the electrode to rotate while burning so that the edges of the crater will burn away evenly- The principal object of the invention is to provide simple means for rotating the electrode while it is burning and for feeding it as is consumed so as to maintain the crater or light source at its proper focusing point.

1 Other objects and advantages will appear as the invention is hereinafter described.

The manner in which the rotating and feeding is accomplished is by providing two sets of constantly rotating'rollers; one set havingits axes parallel with the axis of the electrode and the other set having its axes angularly disposed with respect tothe axis of the electrode. The sets may be so arranged that either, but only at a time, may engage the electrode. The first of these sets may normally engage the electrode and the second set may be moved into engagement in response to slight changes in the position of the crater..

Referring to the drawings wherein I have shown what I now considerto be the pre- "ferred form of my invention:

12, 13 a pair of plates 14, 15.

mechanism shown in Fig. 1 for varying the engagement of the rollers with the electrode. Fig. 5 is a diagrammatic View .of a searchhght showing one method which may be em- I ployed to control the rollers for positioning the crater.

Fig. 6 is a wiring diagram.

In Fig. 5 the Searchlight drum is shown at 1 and is provided at its rear end with the usual parabolic projector 2. The positive and negative electrodes are shown at 3 and 4, with the crater end of the positive electrode at 5 facing the projector and positioned at the focal point thereof.

In Fig. 1 the electrode 3 is shown as supported by the holder 6 mounted at the top of a standard 7. The holder may be provided with a central bore 8 through which the electrode projects and is guided. Heat dissipating fins 9 may also be provided at the front end of the holder.

Within the holder are provided brackets 10,11, upon which are pivotally secured at bers 16, 17, 18, 19 are fixed on said plates for shafts 20, 21, 22, 2,3. Shaft 20 may have fixed thereon a roller 24 and gears 25, 26, while shaft 21 may have a corresponding Bearing mem-v roller 27 and gears 28, 29. Shafts 22, 23 are in turn provided with rollers 30, 31 and gears 32, 33; the said gears meshing with gears 26, 29, respectively. A shaft 34 adapted to be rotated as hereinafter set forth may be provided with a bevel gear 35 meshing with a bevel gear 36 which is,journaled in a bracket 37 carried by the electrode holder. On the same shaft 38 with said bevel gear 36 is a pinion 39 meshing with idlers 40, 41 also journaled in bracket 37 and meshing in turn with gears 25 and 28, respectively. Thus the turnin of shaft 34 in the direction indicated in F1g. 1 will effect rotation of the rollers 24, 27, 30, 31 in the directions indicated in Fig. 2.

42, through brackets 43 or other suitable means to the forward end of the plates 14. 15 so as to hold the rollers 24, 27 normally in engagement with the electrode with sufficient pressure to rotate the latter when the rollers are rotating.

'In order to rotate the plates 14, 15 about their pivots 12, 13 to disengage rollers 24, 27 from the electrode and to press rollers 30, 31 into engagement therewith, I have shown toggle links 44 pivotally connected to the ends of the plates 14, 15 adjacent the spring 42 and also pivotally connected to an actuating rod 45. Upward pressure of this rod willthus overcome the tension of spring 42 and spread the forward ends of the platesv to effect this shifting of the rollers.

The axes of rollers 24, 27 are parallel to the axis of the electrode so that when they are in contact therewith they will cause the electrode to rotate without imparting any other motion to it. The axis of each of rollers 30, 31, however, is at an angle to that of the electrode and as the rollers are on opposite sides of the electrode the inclinations of their axes are in opposite directions to eachother, so that when these rollers are in contact with the electrode they will impart an axial movement as well as a rotary movement to the electrode.

In Fig. 6 the shaft 34 is shown as having a worm' wheel 46 fixed thereon, meshing with a worm 47 onthe shaft 48 of the motor 49. The said motor may be connected across the mains 50 so as to run continuously when the current is on. In this way continuous rotation of rollers 24, 27, and 30, 31 is maintained. The feed control rod may be attached to the core 51 of a solenoid 52 which may be connected across the mains and is preferably provided with a thermostat contact device 53 in its circuit for opening and closing the circuit. The deopen when subjected to heat rays. In Fig.

5 the thermostat 53 is shown as located on the side of the drum 1, an aperture 54 being provided to permit light rays 55 emanating from the crater 5 and reflected by a small mirror 56 on the opposite side of the drum to reach the thermostat.

The mechanism for positioning the negative electrode is not shown, but may be of any suitable type, such for instance as that disclosed in the application of Elmer A. Sperry for feeding mechanism for searchlights, Serial No. 147, 071, filed Feb. 7, 1917, wherein the negative electrode is automatically moved into contact with the positive when the current is turned on, then retracted to draw the arc and thereafter maintained in fixed relation to the positive.

The operation is as follows: When the current is turned on the motor 49 will cause rotation of the rollers 24, 27 and 30, 31

and the solenoid 52 being energized by the rays 55 will strike the thermostat and the change in temperature will cause it to open, deenergizing solenoid 52 and permitting rod 45 to drop. The spring 42 will then shift the rollers, throwing 30, 31 out of engagement and 24, 27 into engagement with the electrode. As the electrode is consumed and the crater begins to reccde the rays 55 will move off from the thermostat and the feed rollers will again be brought into operation. Thus the positive electrode will be rotated throughout the operation of the lamp and the light source within the crater 5 will be automatically moved into the focus of the projector whenever it tends to recede therefrom.

The switch 53 may be used when it is desired to control the feeding of the electrode manually.

In accordance with the provisions of the patent statutes, I have herein described the principle of operation of my invention, together with the apparatus, which I now consider to represent the best embodiment thereof, but I desire to have it understood that the apparatus shown is only illustrative and that the invention can be carried out by other means. Also, while it is designed to use the various features and elements in the combination and relations described, some of these may be altered and others omitted without interfering with the more general results outlined, and the invention extends to such use.

Having described my invention, what I claim and desire to secure by Letters Patent is:

1. In an arc lamp adapted to employ an electrode, electrode rotating and feeding means comprising a roller having its axis parallel to the axis of the electrode, a roller having its axis at an angle to the axis of the electrode, means for rotating said rollers, and means for causing one or the other of said rollers to engage the electrodes.

2. In an arc lamp adapted to employ an electrode, electrode rotating and feeding means comprising a roller having its axis parallel to the axis of the electrode, a roller having its axis at an angle to the axis of the electrode, means for rotating said rollers, and means controlled by the position of the electrode tip for causing one or the other of said rollers to engage the electrode.

3. In an arc lamp adapted to employ an electrode, a member adjacent the electrode and adapted to turn about a pivot, rollers carried by said member on axes angularly disposed with respect to each other, means for rotating said rollers about their respective axes, and means for turning said member about said pivot for causing one or another of said rollers to engage the periphery of the electrode.

4. In an arc lamp adapted to employ an electrode, a member adjacent the electrode and adapted to turn about a pivot, rollers carried by said member on axes angularly disposed with respect to each other, means for rotating said rollers about their respective axes, means controlled by the position of the electrode tip for turning said member about said pivot for causing one or another of said rollers to engage the periphery of the electrode.

5. In an arc lamp adapted to employ an electrode, a roller having its axis parallel to the axis of the electrode, a roller having its axis at an angle to that of the electrode, means for rotating said rollers, means for causing one of said rollers in one position thereof to normally engage the electrode, and in another position thereof to be disengaged from the electrode and cause the other roller to engage the electrode.

6. In combination, a holder for an electrode, means comprising a feed roller for feeding and rotating the electrode within the holder when the roller is in engagement with the electrode, means responsive to the position of the electrode tip for moving said roller into and out of engagement with the electrode, and alternative means for rotating the electrode.

7. The combination with an electrode holder, of mechanism thereon for rotating the electrode, other mechanism thereon for both feeding and rotating the electrode, and means whereby one or the other of said mechanisms may be rendered operative.

8. The combination with an electrode holder, of a plurality of rollers adapted to grip an electrode therebetween and having their axes inclined relative to said electrode axis, means for rotating said rollers, independent means for rotating the electrode, and controllable means for causing either said rollers or said independent means to act upon the electrodes.

9. In an arc lamp, an electrode holder, means associated therewith for rotating an electrode, means for imparting a screw motion to the electrode, and means for causing one or the other of said first and second means to act upon the electrode.'

10. In an arc lamp, a holder for an electrode, a member movable abouta pivot carried by said holder, a plurality of rollers having their axes at an angle to each other mounted on said member, means for turning said member about said pivot for causing one or another of said rollers to engage the electrode, and means for rotating said rollers.

In testimony whereof I have aflixed my signature.

ADELBERT C. MABY. 

